/* Copyright 2013-2015 www.snakerflow.com.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.snaker.engine.impl;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.snaker.engine.Context;
import org.snaker.engine.cfg.Configuration;
import org.snaker.engine.helper.ClassHelper;

/**
 * 简单的服务查找实现类，由 {@link Configuration}设置
 * @author yuqs
 * @since 1.5
 */
public class SimpleContext implements Context {
    /**
     * 上下文注册的配置对象
     */
    private Map<String, Object> contextMap = new HashMap<String, Object>();

    /**
     * 根据服务名称查找对象
     * @param name
     * @return
     */
    @Override
    public boolean exist(String name) {
        return contextMap.get(name) != null;
    }

    /**
     * 对外部提供的查找对象方法，根据class类型查找
     * @param clazz
     * @return
     */
    @Override
    public <T> T find(Class<T> clazz) {
        for (Entry<String, Object> entry : contextMap.entrySet()) {
            if (clazz.isInstance(entry.getValue())) {
                return clazz.cast(entry.getValue());
            }
        }
        return null;
    }

    /**
     * 对外部提供的查找对象实例列表方法，根据class类型查找
     * @param clazz
     * @return
     */
    @Override
    public <T> List<T> findList(Class<T> clazz) {
        List<T> list = new ArrayList<T>();
        for (Entry<String, Object> entry : contextMap.entrySet()) {
            if (clazz.isInstance(entry.getValue())) {
                list.add(clazz.cast(entry.getValue()));
            }
        }
        return list;
    }

    /**
     * 对外部提供的查找对象方法，根据名称、class类型查找
     * @param name
     * @param clazz
     * @return
     */
    @Override
    public <T> T findByName(String name, Class<T> clazz) {
        for (Entry<String, Object> entry : contextMap.entrySet()) {
            if (entry.getKey().equals(name) && clazz.isInstance(entry.getValue())) {
                return clazz.cast(entry.getValue());
            }
        }
        return null;
    }

    /**
     * 对外部提供的put方法
     * @param name
     * @param object
     */
    @Override
    public void put(String name, Object object) {
        contextMap.put(name, object);
    }

    /**
     * 对外部提供的put方法
     * @param name
     * @param clazz
     */
    @Override
    public void put(String name, Class<?> clazz) {
        contextMap.put(name, ClassHelper.instantiate(clazz));
    }
}
